Method of applying concrete



Dec. 1, 1954 T. R. VESSELS 2,696 3 3- METHOD OF APPLYING CONCRETE FiledSept. 13, 1951 2 Sheeis-Sheet 1 WIRE EE/NFOEC/NG INVEN TOR.

Wvzoaae: k. Waste-4s ATTORNEY-5 I Dec; 7, 1954 "r. R. vEssELs 2,696,353

METHOD OF APPLYING CONCRETE Filed Sept. 15, 1951 2 Sheets-Sheet 2 6;;INVENTOR.

r r firfoooez'fil iasas P W M HOIJTZIPELAYA'E BY understood that theword cement taneously United States Patent 2,696,353 lVIETHOD 0FAPPLYING CONCRETE Theodore R. Vessels, Escondido, Califl, assignor toSteam- Cote Corporation, a corporation of California ApplicationSeptember 13, 1951, Serial No. 246,425 Claims. 01. 242-7 Second, toprovide a m thod of applying concrete which utilizes steam jets as thepropelling force to entrain and drive a sand-cement-water mixture athigh velocity against the surface to be coated, the high temperaturesteam jets, not only causing improved hydration but also materiallyreducing curing time. It is to be as used herein means ordinaryhydraulic cement.

Third, to provide a method of this class which incorporates a novelmeans of delivering the sand-cement mixture wherein the sand need not bein a dry state but may have a nominal moisture content without impairingthe operation of the apparatus.

Fourth, to provide a method of applying concrete laminations to surfaceswherein the resulting product may be handled immediately.

Fifth, to provide a method of applying concrete laminations wherein aseries of closely grouped nozzles apply the several laminationssimultaneously as a pipe or mandrel is passed in front of the nozzles,and wherein the character of the laminations, immediately as applied, issuch that the underlying laminations withstand such loads as may beinherent in the wrapping of steel wire reinforcing; thus reinforcingwire may be wrapped simulwith the application of the larninations.

Sixth, to provide a novel method of this class wherein a plurality ofnozzles entrain and mix steam, water, sand and cement and wherein therelative amounts of liquid water suspended in the different steam jetsmay be varied to control the relative moisture contents of the severaljets, thus enabling the coating of metal pipe under conditions in whichthe initial coating may have a deficiency of water to facilitate bondingor, for example, in the manufacture of concrete pipe, the initialcoating may be moisture laden to facilitate removal of the mandrel overwhich concrete pipe is formed.

With the above and other objects in view as may appear hereinafter,reference is directed to the accompanying drawings in which:

Figure 1 is a top or plan view of my apparatus for applying concrete.

Figure 2 is a partial sectional, partial elevational view thereof, takenthrough 22 of Figure 1.

Figure 3 is an enlarged sectional view taken through 3-3 of Figure 1.

Figure 4 is an exaggerated sectional view of a laminated coating onsteel pipe.

Figure 5 is a similar view showing the laminated coating as applied to aremovable mandrel.

My apparatus for applying concrete includes a pair of side frame members1, preferably formed of angle iron and spaced with their upright flangesin confronting relationship to define a channel. The side frames aresuitably mounted on a framework (not shown). Disposed under the sideframes and bridging the channel therebetween, is a conveyer belt, theupper reach of :which is in sliding contact with the underside of the2,696,353 Patented Dec. 7, 1954 ice 2 frame members 1. The conveyer beltis mounted on rollers 3, journaled by bearings suspended under the framemembers. The rearward roller is provided with a drive means 4 which maycomprise a motor, gear drive and chain linkage.

Mounted above the side frames 1 is a hopper 5 having a discharge enddirected between the side frames. The conveyer belt forms a closure forthe lower end of the hopper. The forward side of the hopper isprovidedbetween the side frames 1 with a vertically adjustable gate 6, which maybe raised and lowered by elevator means 7, comprising a hand operatedshaft, gear and rack means. The position of the lower edge of the gate 6above the conveyer belt, determines the thickness of the layer ofmaterial which may be withdrawn from the hopper as the beltis driven. Itis intended that the hopper contain a sand-cement mixture. It is notnecessary that the sand be dried or otherwise especially treated toremove its normal moisture content. This is of importance for the reasonthat heretofore it has been necessary to maintain the sand in a dry,free flowing state.

Hinged on the shaft which carries the forward roller 3, is a bracket 8which supports a manifold structure 9. The manifold'structure isprovided with an upstanding funnel 10 which embraces the discharge endof the conveyer belt so that all material passing between the sideframes is discharged into the funnel. The funnel 10 is provided with arow of outlet ports, each receiving a tube which forms an inner nozzle11.

The inner nozzles 11 are jacketed by a steam chest 12 having dependingthreaded bores surrounding the inner nozzles and adapted to receiveouter nozzles 13. The inner nozzles project into their correspondingouter nozzles and form therewith venturi throats 14. The steam chest 12extends laterally from the funnel, and its side walls converge toterminate in a nipple for connection to a steam valve 15.

A water nozzle 16 projects into the steam chest near the steam valve 15through a packing gland 17. The water nozzle is connected to a watervalve 18. The water nozzle is provided with a laterally directed orificeor orifices to deliver a stream of water toward the series of innernozzles 11. The water nozzle is rotatable so that the relativequantities of water delivered to the series of nozzles may be varied.

The'steam valve and water valve are preferably supplied through hoses sothat the entire manifold structure may be moved between its normalposition in which the nozzles are directed vertically downward, to aninclined position indicated by dotted lines in Figure 2' Operation of myapparatus is as follows: Steam and water are supplied to the steam chestand caused to jet downwardly through the outer nozzles 13, creating anegative pressure in the inner nozzles 11 and funnel 10. Simultaneously,the conveyer belt carries a sand-cement mixture to the funnel 10 wheresuch mixture falls by gravity, aided by the negative pressure producedat the discharge ends of the inner nozzles. The sand-cement mixture isentrained with the steam and water as it passes through and dischargesat high velocity from the outer nozzles 13. A pipe or other surface tobe coated. is rotated and passed underneath the discharge ends of thenozzles 13, the direction of movement being in the common plane of thesenozzles.

It should be observed that the sand-cement mixture, contained in thehopper, may be formed with sand containing a normal amount of moisture,that is, the sand may be used as it comes normally from a storage bineven though it may be damp. This is of primary importance for the reasonthat the cost of drying sand and maintaining it in such condition, issubstantial. The use of damp sand is made possible by the uniquearrangement of the conveyer belt which wipes across the underside of thestorage bin to withdraw a layer of the sand-cement mixture, coupled withthe arrangement wherein the sand-cement mixture is poured by gravityfrom the discharge end of the conveyer and caused to fall unconsolidatedand freely into the funnel 10. The sand-cement mixture does notaccumulate in the funnel but is immediately entrained in the downwardlyflowing air created by the jetting action of the steam and thusaccelerated to a high velocity by the steam jet. It will be observedthat the sand-cementmixture is maintained principally in the centralportion of the discharging column of the sand, cement, water and steamso that the inneriwalls. of the nozzles 1-3 are continuallywashedi bythe steam and water and accumulations of cementiare avoided;

The steanris not only more economicalto produce than compressed air buthas several additionalradvantages. The steam virtually eliminates: anydust; If air is .used, a large: quantity ofdustnisproduced; 'This'dustconsists. largely of cement, which not only is lost but constitutes aworking hazard for the. operator, requiring the use of arespirator mask-As'will be brought out? in more detail hereinafter, the 'hightemperature of the steam materially improves hydration and substantiallyreduces curingrtime. However, my apparatus" is capable of successful'operation by use of air. in place of steam.

Adjustmentof the water. supply, not only as to its total volume, butalso as to its distribution to the several nozzles, is of. primaryimportance. For instance, in the applying of concrete laminations tosteel pipe, a moisturedeficiency first coating is desired, whereasthe:formingzof concrete pipe over collapsible mandrel, a greatermoisture content is desired; Considering first the coating of steelpipe, indicated by P in Figures 2, 3 and 4, it has been foun'dthat byuse of a moisture deficiency first coating, a remarkably tenacious bondis obtained.

By use of a moisture deficient steam jetted mixture of sand and cement,delivered at high velocity, a scouring action is obtained whichthoroughly cleans the pipe. A large. percentage ofthe sand reboundsfromthe pipe so that the resulting coating has'a concentration offinesand cement. Most of the cement remains to coat the pipe, for the sand,which rebounds, is virtually free'of' cement coating andis capable ofbeing salvaged for reuse. This scouring action, coupled with theimmediate application of" the. cement, eliminates any oxide coatingwhich would reduce bonding between the concrete and the pipe.

In the jet application of the laminations, there-is a tendency for thewater content to concentrate atthe radially inner surface; thus, themoisture content of the first coating or lamination tends to collect onthe surface of'the pipeand prevents a good bond between the cement andthe pipe. By providing a moisture deficient first layer, anyconcentration of moisture at the surface of the pipe is.immediatelydrawn back into the lamination. To insure complete hydration of theinitial lamination, the second and third laminations are not moisturedeficient but may containa slight excess for absorption into the initiallamination.

It has been found desirable to provide a moisture deficient final costor lamination, although this is not as vital as in the case of the firstcoating.

In the manufacture of concrete pipe wherein the'laminations' are appliedover a collapsible mandrel, indicated by M' in Figure 5, itis'desira'ble to produce'a moisture layer between the first coating andthe mandrel. Consequently, instead of producing a moisture deficientfirst coating, adequate quantity of water is supplied to produceamoisture film which will avoid any bonding and facilitate removal of themandrel.

It should be understood thatin any case, the moisture content of thevarious laminations is held to a minimum so that the resulting mixtureis damp rather'than wet. It has been found that with proper control ofthe moisture content, coupled with the action of the steam to promotehydration of initial setting, that the concrete pipe or concrete cladmetal pipe may be handled immediately after being coated. By handling,it is meant that the pipe may be removed from the carriage or othermeans whereby it is moved past the nozzles and placed on runners orother supports, and that within a very short time, the pipe may bestacked for storage without danger of injury to the concrete.

It will be observed thtat thenozzles are closely grouped so that as thepipe or mandrel is moved past the nozzles, each lamination is exposedfor only a matter of seconds before the succeeding lamination isapplied. Even though this be the case, initial setting-of the concretetakes place so rapidly that it is possible to apply wire reinforcing asindicated by W in Figures2, 3, 4 and 5. For example, if four laminationsA-,B, C, D are applied to the pipe, the wire reinforcing W may beintroduced :between thesecond and third nozzles. so. as to be im- .tion:of moisture from one bedded between laminations B and C. It should beborne'in mind" that the wire reinforcingis applied under tension, yetthere appears to be little or no crushing or displacement of theunderlying laminations. Heretofore, it has been necessary to applyinitial laminations, allow the laminations to cure partially and thenapply the Wire reinforcing and outer laminations. This has requireddouble handling of the pipe whereas in the present instance, bothcoating and reinforcing. are accomplished simultaneously.

As' will be best observed in the diagrammatical views of Figures 4 and5, each lamination is not uniform throughout its thickness, that is, theradially inner side of each lamination contains a greater percentage offines and cement than the outer side. This accomplishes two things,first, after the concrete has set, the innermost surface of eachlamination is highly impervious to moisture; second, the roughness ofthe outermost surface of each lamination provides excellent bond withthe confronting surface of the covering lamination. In the coating ofsteel pipe, this prevents migration of moisture to the pipe, and in the.forming of concrete pipe, prevents the outward. migration of watercarried by the pipe.

It will be'observed that the amount of' water supplied through the waternozzle is adjusted to compensate for the initial moisture content of thesand. In addition, it will be observed that the relative volume of Watersupplied to each of the nozzles .is easily regulated by turning thewatersupp'ly'nozzle. In order to facilitate adjustment, and in order toavoid coating of the pipe during return movement of the carriage orother structure (not shown) which supports the pipe, the entire manifoldor nozzle assembly maybe tilted to the dotted line position shown inFigure 2.

Having fully described my invention, it is to be understood that I donot wish to be limited to the details herein: set forth, but myinvention is of the full scope of the appended claims.

I claim:

'1. A method of applying cementitious material to a surface,characterized by: establishing a downwardlydirected jet containingliquid water suspended in steam in a substantially upright open-endedtubular structure; feeding by gravity at a predetermined rate intotheupper end of said tubular structure an unconsolidated free fallingmixture of. sand and hydraulic cement to be wetted and entrained by saidjet; and directing the entraining jets and their contentsupon: a surfaceto be coated.

2. A methodof applying cementitious material to surfaces, characterizedby: establishing a series of downwardly directed motive gas jetscontaining liquid water'in suspenslon'in a series of substantiallyupright open ended tubular structures; simultaneously pouring into theupper ends of said tubular structures an unconsolidated free fallingmixture of sand and hydraulic cement to be wetted and entrained by saidjets; and directing the entraining jets and their'contents upon surfacesto be coated.

3. A method of applying cementitious material to sur faces,characterized by: establishing a series of downwardly directed steamjets in a series of substantially upright open' ended tubularstructures; introducing preselected different quantities of liquid waterinto said steam jets for suspension therein; simultaneously pouring intothe upper ends-of said tubular structures an unconsolidated free fallingmixture. of sand and hydraulic cement for entrainment in said steam jetsto produce sand-cement streams having different moisture content; anddirecting the entraining jets and their contents upon surfaces to becoated.

4. A method of applying cementitious laminations to a. surface,characterized by: establishing a series of downwardly directed, motivegas jets containing liquid water in suspension in a series ofsubstantially upright contiguous open-ended tubular structures;simultaneously pouring intothe upper ends of'said tubular structures anunconsolidated free falling mixture of sandandhydraulic cement to bewetted and entrained by said jets to issue from said tubular structuresas streams; passingthe surface to be coated across said contiguousstreams for sequential application of the contents of said. streams toform cementitious laminations; regulating the relative moisture contentof said streams to produce laminations having different initial moisturecontent, but permitting migralamination: to the other to effectsubsequent substantially uniform distribution of moisture and thereforeuniform hydration of the cement.

5. A method of applying cementitious laminations to a surface,characterized by: establishing a series of downwardly directed, motivegas jets containing liquid water in suspension in a series ofsubstantially upright contiguous open ended tubular structures;simultaneously pouring into the upper ends of said tubular structures anunconsolidated free falling mixture of sand and hydraulic cement to bewetted and entrained by said jets to issue from said tubular structuresas streams; and passing the surface to be coated across the contiguousstreams issuing from said tubular structures to cause the sand andhydraulic cement and water to deposit thereon in a series oflaminations.

6. A method as set forth in claim wherein the liquid water content ofsaid streams diifers whereby said laminations have different initialmoisture content, but migration of water between the laminations ispermitted thereby to establish subsequently a substantially uniformdistribution of moisture and uniform hydration of the cement.

7. A method of applying cementitious laminations to pipe, characterizedby: establishing a row of downwardly directed jets containing liquidwater suspended in steam and surrounding a row of substantially uprightopenended tubular structures; feeding by gravity at a predetermined rateinto the upper end of each tubular structure an unconsolidatedfree-falling mixture of sand and hydraulic cement for entrainment bysaid jets; and rotating a pipe with its axis substantially horizontaland passing said pipe longitudinally in a plane common to that of saidjets and tubular structures, whereby said jets apply simultaneously aseries of sand-cement laminations to said pipe.

8. A method of applying cementitious laminations to pipe, characterizedby: establishing a row of downwardly directed jets containing liquidwater suspended in steam and surrounding a row of substantially uprightopen-ended tubular structures; feeding by gravity at a predeterminedrate into the upper end of each tubular structure an unconsolidatedfree-falling mixture of sand and hydraulic cement for entrainment bysaid jets; rotating a pipe with its axis substantially horizontal andpassing said pipe longitudinally in a plane common to that of said jetsand tubular structures, whereby said jets apply simultaneously a seriesof sand-cement laminations to said pipe; and wrapping wire reinforcinghelically on said pipe starting in a region between a pair of said jetswhereby said wire reinforcing is applied simultaneously with and betweensaid laminations.

9. A method of applying cementitious material to a pipe, characterizedby: establishing at least one downwardly directed jet containing liquidwater suspended in steam and surrounding at least one substantiallyupright open-ended hollow structure; feeding by gravity at apredetermined rate into the upper end of said hollow structure anunconsolidated free-falling mixture of sand and hydraulic cement forentrainment by said jet; and rotating a pipe with its axis substantiallyhorizontal and passing said pipe longitudinally past said jet and hollowstructure, whereby said jet applies a coating of sand-cement to saidpipe.

10. A method of applying cementitious material to a pipe, characterizedby: establishing at least one downwardly directed jet containing liquidwater suspended in steam and surrounding at least one substantiallyupright open-ended hollow structure; feeding by gravity at apredetermined rate into the upper end of said hollow struc ture anunconsolidated free-falling mixture of sand and hydraulic cement forentrainment by said jet; rotating a pipe with its axis substantiallyhorizontal and passing said pipe longitudinally past said jet and hollowstructure, whereby said jet applies a coating of sand-cement to saidpipe; and simultaneously with the application of said sand-cementcoating, wrapping wire reenforcing helically around said pipe in aregion within the axial extremities of said jet, whereby saidsand-cement coating underlies and overlies the wire reinforcing therebyto completely embed wire reenforcing.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 984,254 Akeley Feb. 14, 1911 1,751,343 Mack Mar. 18, 19301,979,656 Whitman Nov. 6, 1934 2,428,284 Krogel Sept. 30, 1947 2,495,540Nichols et al. Jan. 24, 1950 2,543,517 Anderson Feb. 27, 1951

